Scaling relationships in indentation of power-law creep solids using self-similar indenters

We use dimensional analysis to derive scaling relationships for self-similar indenters indenting solids that exhibit power-law creep. We identify the parameter that represents the indentation strain rate. The scaling relationships are applied to several types of indentation creep experiment with constant displacement rate, constant loading rate or constant ratio of loading rate over load. The predictions compare favourably with experimental observations reported in the literature. Finally, a connection is found between creep and 'indentation-size effect' (i.e. changing hardness with indentation depth or load).     

Surface energy of free clusters of bubbles: An estimation

We propose an approximate equation for the surface energy of two-dimensional free bubble clusters which we compare with exact calculations of the surface energy of symmetrical clusters consisting of a central bubble surrounded by one or two shells of bubbles of two different areas. The accuracy of the equation is good for relatively narrow distributions of the areas and of the number of sides of the bubbles but underestimates the energy for large widths of those distributions. We propose a similar approximate equation for the surface energy of three-dimensional clusters.     

Analysis of sintering of two cylindrical particles by lattice or grain-boundary diffusion at the initial stage

The sintering of two cylindrical particles by lattice or grain-boundary diffusion at the initial stage is analysed by a variational principle and use of the continuity equation. The expression for the growth rate by lattice or grain-boundary diffusion indicates that the length of the neck increases as a power of time.     

A short and very short form of the physical self-inventory for adolescents: Development and factor validity

ObjectivesThe Physical Self-Inventory (PSI)—a French adaptation of the Fox and Corbin's [1989. The Physical Self-Perception Profile: Development and preliminary validation. Journal of Sport and Exercise Psychology, 11, 408–430] Physical Self-Perception Profile—was originally developed for use with adults and no study has systematically verified its psychometric properties in adolescent populations. Additionally, this instrument remains too long to be efficiently completed in combination with multiple other instruments within extensive longitudinal or idiographic studies. The purpose of the present investigation was thus threefold: (a) testing the factor validity and reliability of the original PSI in a sample of adolescents; (b) developing and testing the factor validity and reliability of a very short (i.e., two items per scale) form of the PSI in a sample of adolescents; and (c) testing the equivalence of the factor pattern, structural parameters, latent mean structure, and criterion-related validity of both forms of the PSI.DesignStructural equation modeling approach.MethodTwo samples participated in this series of studies. In Study 1, a sample of 1018 adolescents completed the adult PSI (25 items) and was randomly split in two sub-samples. In Study 2, a new sample of 320 adolescents completed a very short form of the PSI (PSI-VSF). Factorial validity and gender and multigroup invariance of these instruments (PSI, PSI-VSF) were tested using confirmatory factorial analysis (CFA) and structural equation modeling (SEM).ResultsIn Study 1, CFA and SEM analyses provided evidence for the factor validity and reliability of a short (PSI-SF: 18 items) and very short (PSI-VSF: 12 items) form of the PSI for adolescents. In Study 2, CFAs and SEMs supported the equivalence of the factor pattern, structural parameters, latent mean structure, and criterion-related validity of both forms of the PSI (i.e., PSI-SF, PSI-VSF).ConclusionThe present results thus provide preliminary evidence regarding the reliability and validity of a short and a very short form of the PSI for French adolescents.     

Latent state–trait theory: An application in sport psychology

ObjectiveQuestionnaires are often applied in sports psychology to measure a person's trait or state. However, the extent to which the questionnaire captures differences because of trait or state influences is often unclear. The latent state–trait (LST) theory offers the opportunity to separate both variance sources. This separation allows estimating specific reliability coefficients.DesignThe present paper gives a theoretical introduction to LST and its basic ideas. Using a real data set with N = 156 athletes we exemplify the steps necessary to derive the LST coefficients. All athletes filled out a comprehensive inventory assessing competitive anxiety on two occasions.MethodThe data are analysed with structural equation models based on LST principles.ResultsThe results confirm the questionnaire's trait saturation.ConclusionFinally, results are discussed in light of practical and theoretical implications.     

On epistemic and moral certainty: A wittgensteinian approach

Abstract

Epistemic and moral certainities like ‘This is a hand’ or ‘Killing people is evil’ will be interpreted as constitutive rules of language games, such that they are unjustifiable, undeniable and serving as obliging standards of truth, goodness and rationality for members of a community engaging in the respective practices.     

Appreciation of nature and appreciation of environmental protection: How stable are these attitudes and which comes first?

IntroductionAttitude toward nature and attitude toward environmental protection are two separate but correlated attitudes. Little is known about the two attitudes’ stability/volatility over time, despite the practical value of such knowledge.Objectives & methodUsing longitudinal survey data from 251 adults in a cross-lagged structural equation model, we assessed the degree of spontaneous (i.e., unprompted) change in the two attitudes. We also considered whether such change could provide evidence regarding causal direction; causation could go in either of two directions between the two attitudes, or it could even be bi-directional.ResultsWe corroborated the substantive connection between attitude toward nature and attitude toward environmental protection; however, the absence of change in the attitudes despite the passage of two years disallows reliable statements about causal direction.ConclusionIt is possible to protect the environment by encouraging appreciation of nature, but change in attitude toward nature and attitude toward environmental protection may be difficult to achieve with mature individuals.     

Ignorance and Virtue

Abstract

Julia Driver has argued that there is a class of virtues that are compatible with or even require that an agent be ignorant in some respect. In this paper I argue for an alternative conception of the relationship between ignorance and virtue. The dispositions constitutive of virtue must include sensitivity to human limitations and fallibility. In this way the virtues accommodate ignorance, rather than require or promote it. I develop my account by considering two virtues in particular: tolerance (the paradigm for my account) and modesty (which Driver employs as the paradigm for her account). Although several philosophers have offered alternatives to Driver's account of modesty and others have discussed tolerance as a moral virtue, an adequate account of the role of ignorance in the specification of the virtues generally has yet to be provided. I believe that similarities between the two virtues are instructive for defining that role.     

Approximant phases,phason planes and domain-boundary networks in Al−Ni−Rh alloys

Structurally complicated ξ′- and ξ-phases have been found, for the first time, in as-cast Al₇₃Ni₅Rh₂₂ and Al₇₅Ni₁₅Rh₁₀ alloys. The lattice parameters of these two phases were determined by means of electron diffraction and high-resolution transmission electron microscopy (HREM). These two phases have similar orthorhombic structures but with different lattice parameters of a?=?23.2?Å, b?=?16.4?Å, c?=?12.0?Å for the ξ′-phase and a?=?20.3?Å, b?=?16.4?Å, c?=?14.8?Å for the ξ-phase. A new two-dimensional domain-boundary network has also been observed in these two phases. Domain boundaries with normals closely parallel to the [001] direction are actually phason planes represented by a translation vector of r?=(1/2)a?+(1/2τ)c in the ξ′-phase and r=±(1/2τ²) a?+(τ/2)c in the ξ-phase, whereas the newly-found wide and zigzag boundaries perpendicular to the above set were attributed from the step-like boundary structures of domains related by a translation vector of r?=(1/τ)((1/2)a?+(1/2τ)c). The structural difference between the two types of planar faults is discussed.     

Humor as a protective factor against anxiety and depression

Background/ObjectivesEven though humor its part of everyday life, only in the last 40 years has Psychology begun to discern its impact on mental health. The aim of this paper is to explore the role that humor styles may have as protectors against anxiety and depression and their relationship with optimism.MethodA sample of 804 participants (M = 39.28; SD = 14.71) was used to analyze the uses of humor, optimism and clinical symptoms of anxiety and depression. In addition, the influence of sociodemographic variables such as sex, geographic location, age and educational level on different uses of humor was studied. Through an analysis of structural equations, the variables that had a protective or facilitating role in depression and anxiety were analyzed.ResultsMen and women differ in the use of a more aggressive humor style, and the use of affiliative humor styles decreases with age. The structural equation model indicated a good fit to the proposed theoretical model.ConclusionsHumor is a tool of everyday life and it can act for or against an individual’s mental health.     

Passion and performance attainment in sport

ObjectivesTo test a performance-attainment model derived from the Dualistic Model of Passion [Vallerand et al. (2003). Les passions de l’âme: On obsessive and harmonious passion. Journal of Personality and Social Psychology, 85, 756–767] that posits that both harmonious and obsessive passions are positive predictors of deliberate practice that, in turn, is a positive predictor of performance.DesignA prospective design was used in the present study.Methods and resultsThe basic model was tested in two studies using structural equation modeling. Results from Study 1 with 184 high school basketball players indicated that both harmonious and obsessive passions were positive predictors of deliberate practice, which, in turn, was a positive predictor of objective performance. The results of Study 2, conducted with 67 synchronized swimming and water-polo athletes conceptually replicated those from Study 1. Furthermore, results differentially linked the two passions to achievement goals and subjective well-being (SWB). Specifically, harmonious passion was a positive predictor of mastery goal pursuit and SWB, whereas obsessive passion was a positive predictor of mastery, performance-approach, and performance-avoidance goal pursuit and was unrelated to SWB. Mastery goals were positive predictors of deliberate practice, which was a direct positive predictor of performance, whereas performance-avoidance goals were direct negative predictors of performance.ConclusionsIt appears that there are two paths to high-level performance attainment in sport, depending if harmonious or obsessive passion underlies sport engagement. While the path from harmonious passion is conducive to high levels of performance and living a happy life, that from obsessive passion is less reliably related to performance attainment and is unrelated to happiness.     

The development of a short scale measuring aggressiveness and anger in competitive athletes

ObjectivesThe study of aggression and anger in competitive sport relies on accurate and economical measurement via observation, interview and questionnaire. Unfortunately, extant questionnaires have been criticised for having poor validity, are not sport specific, or reflect mood states rather than trait qualities. Therefore, a measure of trait anger and aggressiveness in competitive athletes was developed.MethodA list of statements representing aggressiveness and anger was generated and distributed to competitive athletes from diverse sports. Exploratory and confirmatory analyses were used to verify the theoretically predicted factor structure. Correlations with an extant measure of aggression and anger were used to ascertain concurrent validity. Discriminant validity was tested by comparing males with females, and aggressive with non-aggressive footballers.ResultsA 12-item scale (Competitive Aggressiveness and Anger Scale, CAAS) consisting of two subscales was derived using principal component factor analysis with oblimin rotation. Confirmatory factor analysis using structural equation modelling confirmed the overall structure. Test–retest correlation, construct and discriminant validities were good, supporting the utility of the scale as a measure of athlete trait aggressiveness and anger.ConclusionsThe CAAS appears to be a useful measure of athletic anger and aggressiveness. Its brevity and ability to discriminate aggressive from non-aggressive athletes should prove useful for future research concerning aggressive behaviour in competitive athletes.     

The contribution of role satisfaction,meaning in life and work–home conflict to explaining well-being among working grandparents

Background and objectives: The study aimed to examine the relationship of satisfaction with occupied roles as well as the sense of meaning in life and experience of work–home conflict to well-being among working grandparents in Israel.

Design and methods: The research sample consisted of 316 employed grandparents aged 50–80 (153 grandfathers and 163 grandmothers), who were employed in various types of organizations. Data were collected using structured questionnaires. Structural equation modeling was used for data analysis.

Results: The research findings indicate that the sense of meaning in life mediated the relationship between role satisfaction and the two types of work–home conflict. A significant relationship was found between “work interferes with family” conflict and negative affect. Higher personal resources were associated with higher meaning in life. Gender was not related to the experience of work–home conflict or to any of the outcome variables.

Conclusions: The centrality of meaning in life in the model that explains the experience of work–home conflict and its outcomes among working grandparents, derives from its mediating role in the relationship between the experience of role satisfaction and both types of role conflict, as well as from its direct impact on positive and negative affect.     

Initial sintering of cylindrical particles of different sizes by surface diffusion

Sintering of two cylindrical particles of different sizes by surface diffusion at the early stage is theoretically analysed. Formulae for the neck growth rate are derived using a variational principle and the continuity equation of vacancies. The size difference between two particles is found to influence the growth rate of the neck only when the difference is large.     

Self-determination of contextual motivation,inter-context dynamics and adolescents’ patterns of sport participation over time

ObjectivesPrevious studies have shown the heuristic qualities of self-determination theory constructs to predict sport persistence. The purpose of this study was to extend these researches by focusing on the conflicting or instrumental relationship between sport and other life contexts (i.e., school and friendship) to enhance the understanding of this phenomenon.DesignA correlational longitudinal field design was used, including two data collections over 1 year.MethodParticipants were 446 French high school students (mean age=13.85). Self-determined motivation toward sport, school and friendship, perceived conflicts versus instrumental relationships between sport and the other contexts, and sport participation during leisure time were assessed at wave 1. One year later, participants completed the same self-report measure of sport practise.ResultsStructural equation modelling revealed that (a) self-determined motivation toward sport, education and friendship was significantly related to the levels of conflict and instrumentality between those contexts and (b) a competing relationship between sport and education was negatively linked to sport participation at Time 2, whereas the other inter context relationships were not.ConclusionFindings suggest that other contexts like education can undermine sport investment among adolescents.     

Power-law island size distributions and the Avrami model

The island size distribution in the early stages of thin-film deposition is simulated using the Avrami model and is shown to follow closely a power-law form for both two- and three-dimensional island growth. This model applies to systems where the time-averaged monomer density is constant across the substrate, as occurs for example when the mean free path of the diffusing monomers is limited. It offers a possible explanation for recently observed island size distributions which are continuously decreasing functions of size in certain systems. The distribution of nearest-neighbour separations of the islands is also considered and it is shown that this distribution can be used to distinguish between island arrays formed in the Avrami model and those of deposition-diffusion-aggregation models.     

Ethnicity and the theory of planned behavior in an exercise context: A mediation and moderation perspective

ObjectivesMost college students fail to meet recommended exercise levels and ethnic disparities in participation are apparent. The present study examined the moderating and mediating relationships among ethnicity, the theory of planned behavior (TPB), and exercise, and identified common and ethnic-specific beliefs related to exercise.MethodCollege students completed a baseline TPB questionnaire and an exercise assessment at either two-week (n=237 blacks; n=176 whites) or two-month (n=280 blacks; n=273 whites) follow-ups.DesignOne week and two month longitudinal designs.ResultsStructural equation modeling showed that the TPB was invariant by ethnicity in both samples with affective attitudes and perceived behavioral control being significant predictors of intention, which in turn, significantly predicted exercise. Furthermore, analyses showed that the TPB had a small mediating effect on the ethnicity/exercise relationship in both samples. Finally, common and ethnic-specific beliefs were identified that varied by sample.ConclusionThe TPB is a useful framework to explain exercise behavior in black and white students; however, its ability to explain the ethnic disparity in exercise may be limited.     

Deconstructing trait anxiety: a network perspective

Background and objectives: For decades, the dominant paradigm in trait anxiety research has regarded the construct as signifying the underlying cause of the thoughts, feelings, and behaviors that supposedly reflect its presence. Recently, a network theory of personality has appeared. According to this perspective, trait anxiety is a formative construct emerging from interactions among its constitutive features (e.g., thought, feelings, behaviors); it is not a latent cause of these features.

Design: In this study, we characterized trait anxiety as a network system of interacting elements.

Methods: To do so, we estimated a graphical gaussian model via the computation of a regularized partial correlation network in an unselected sample (N?=?611). We also implemented modularity-based community detection analysis to test whether the features of trait anxiety cohere as a single network system.

Results: We find that trait anxiety can indeed be conceptualized as a single, coherent network system of interacting elements.

Conclusions: This radically new approach to visualizing trait anxiety may offer an especially informative view of the interplay between its constitutive features. As prior research has implicated trait anxiety as a risk factor for the development of anxiety-related psychopathology, our findings also set the scene for novel research directions.